Large quasar group

A large quasar group (LQG) is a collection of quasars (a form of supermassive black hole active galactic nuclei) that form what are thought to constitute the largest astronomical structures in the known universe. LQGs are thought to be precursors to the sheets, walls and filaments of galaxies found in the relatively nearby universe.[1]

Prominent LQGs

On January 11, 2013, the discovery of the Huge-LQG was announced by the University of Central Lancashire, as the largest known structure in the universe by that time. It comprises 73 quasars and has a minimum diameter of 1.4 billion light-years, but over 4 billion light-years at its widest point.[2] According to researcher and author, Roger Clowes, the existence of structures with the size of LQGs was believed theoretically impossible. Cosmological structures had been believed to have a size limit of approximately 1.2 billion light-years.[3][4]

List of LQGs

An artist's impression of a single quasar powered by a black hole with a mass two billion times that of the Sun
Large Quasar Groups
LQG Date Mean Distance Dimension # of quasars Notes
Webster LQG
(LQG 1)		 1982 z=0.37 100 Mpc 5 First LQG discovered. At the time of its discovery, it was the largest structure known.[1][5][6]
Crampton–Cowley–Hartwick LQG
(LQG 2, CCH LQG, Komberg-Kravtsov-Lukash LQG 10)		 1987 z=1.11 60 Mpc 28 Second LQG discovered [1][5][7]
Clowes–Campusano LQG
(U1.28, CCLQG, LQG 3)		 1991 z=1.28
  • longest dimension: 630 Mpc
34 Third LQG discovered [5][8]
1995 z=1.9 120 Mpc/h 10 Discovered by Graham, Clowes, Campusano.[1][7][9]
1995 z=0.19 60 Mpc/h 7 Discovered by Graham, Clowes, Campusano; this is a grouping of 7 Seyfert galaxies.[1][7][9]
Komberg–Kravtsov–Lukash LQG 1 1996 z=0.6 R=96 Mpc/h 12 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 2 1996 z=0.6 R=111 Mpc/h 12 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 3 1996 z=1.3 R=123 Mpc/h 14 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 4 1996 z=1.9 R=104 Mpc/h 14 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 5 1996 z=1.7 R=146 Mpc/h 13 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 6 1996 z=1.5 R=94 Mpc/h 10 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 7 1996 z=1.9 R=92 Mpc/h 10 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 8 1996 z=2.1 R=104 Mpc/h 12 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 9 1996 z=1.9 R=66 Mpc/h 18 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 11 1996 z=0.7 R=157 Mpc/h 11 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Komberg–Kravtsov–Lukash LQG 12 1996 z=1.2 R=155 Mpc/h 14 Discovered by Komberg, Kravtsov, Lukash.[1][7]
Newman LQG
(U1.54)		 1998 z=1.54 150 Mpc/h 21 Discovered by P.R. Newman et al. This structure is parallel to the CCLQG, with its discovery, suggesting that the cellular structure of sheets and voids already existed in this era, as found in later void bubbles and walls of galaxies.,[1][8]
Tesch–Engels LQG 2000 z=0.27 140 Mpc/h 7 The first X-ray selected LQG.[1]
U1.11 2011 z=1.11
  • longest dimension: 780 Mpc
 38 [5][8]
Huge-LQG
(U1.27)		 2013 z=1.27
  • characteristic size: 500 Mpc
  • longest dimension: 1240 Mpc
 73 The largest structure known in the observable universe[5][10] until it was eclipsed by the Hercules–Corona Borealis Great Wall found one year later.[11][12][13]

See also

Further reading

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 R.G.Clowes; "Large Quasar Groups - A Short Review"; 'The New Era of Wide Field Astronomy', ASP Conference Series, Vol. 232.; 2001; Astronomical Society of the Pacific; ISBN 1-58381-065-X ; Bibcode: 2001ASPC..232..108C
  2. ↑ Wall, Mike (2013-01-11). "Largest structure in universe discovered". Fox News.
  3. ↑ Wall, Mike (2013-01-11). "Largest Structure In Universe, Large Quasar Group, Challenges Cosmological Principle". The Huffington Post.
  4. ↑ Clowes, Roger; Kathryn A. Harris, Srinivasan Raghunathan, Luis E. Campusano, Ilona K. Söchting, Matthew J. Graham.; Raghunathan, S.; Campusano, L. E.; Sochting, I. K.; Graham, M. J. (January 11, 2013). "A structure in the early Universe at z ∼ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology". Monthly Notices of the Royal Astronomical Society. 429 (4): 2910. arXiv:1211.6256Freely accessible. Bibcode:2013MNRAS.429.2910C. doi:10.1093/mnras/sts497.
  5. 1 2 3 4 5 Clowes, Roger G.; Harris, Kathryn A.; Raghunathan, Srinivasan; Campusano, Luis E.; Soechting, Ilona K.; Graham, Matthew J.; "A structure in the early universe at z ~ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology"; arXiv:1211.6256 ; Bibcode: 2012arXiv1211.6256C ; doi:10.1093/mnras/sts497 ; Monthly Notices of the Royal Astronomical Society, 11 January 2013
  6. ↑ Webster, Adrian (May 1982). "The clustering of quasars from an objective-prism survey". Monthly Notices of the Royal Astronomical Society. 199: 683–705. Bibcode:1982MNRAS.199..683W. doi:10.1093/mnras/199.3.683.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Boris V. Komberg, Andrey V. Kravtsov, Vladimir N. Lukash; "The search and investigation of the Large Groups of Quasars"; arXiv:astro-ph/9602090 ; Bibcode: 1996astro.ph..2090K ;
  8. 1 2 3 Clowes, Roger; Luis E. Campusano, Matthew J. Graham and Ilona K. S¨ochting (2001-09-01). "Two close Large Quasar Groups of size ∼ 350 Mpc at z ∼ 1.2". Mon. Not. R. Astron. Soc. arXiv:1108.6221Freely accessible. Bibcode:2012MNRAS.419..556C. doi:10.1111/j.1365-2966.2011.19719.x.
  9. 1 2 Graham, M. J.; Clowes, R. G.; Campusano, L. E.; "Finding Quasar Superstructures"; Monthly Notices of the Royal Astronomical Society, Vol. 275, NO. 3/AUG1, P. 790, 1995 August; Bibcode: 1995MNRAS.275..790G
  10. ↑ ScienceDaily, "Biggest Structure in Universe: Large Quasar Group Is 4 Billion Light Years Across", Royal Astronomical Society, 11 January 2013 (accessed 13 January 2013)
  11. ↑ Horvath I.; Hakkila J.; Bagoly Z. (2014). "Possible structure in the GRB sky distribution at redshift two".
  12. ↑ Horvath I., Hakkila J., and Bagoly Z.; Hakkila, J.; Bagoly, Z. (2013). "The largest structure of the Universe, defined by Gamma-Ray Bursts". 1311: 1104. arXiv:1311.1104Freely accessible. Bibcode:2013arXiv1311.1104H.
  13. ↑ Klotz, Irene (2013-11-19). "Universe's Largest Structure is a Cosmic Conundrum". Discovery. Retrieved 2013-11-22.
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